What does the abbreviation "NPO" stand for?

The abbreviation "NPO" stands for "nothing by mouth," which is commonly used in medical settings to indicate that a patient must abstain from all oral intake, including food, fluids, and medications, for a specified period of time. This instruction is often given prior to surgery, specific medical tests, or procedures to ensure the patient's safety and improve the efficacy of the treatment.

The term "nothing by mouth" is important as it helps mitigate the risk of aspiration—that is, food or liquid entering the lungs—and ensures that the stomach is empty before anesthesia is administered or certain tests are conducted. In medical documentation and communication, "NPO" serves as a clear and concise directive that healthcare providers understand universally.

Other options presented include variations that do not accurately reflect the standard usage of "NPO." They either misinterpret the term or introduce concepts not associated with the abbreviation as used in medical contexts. Therefore, the choice that accurately represents the meaning and intent of "NPO" is "nothing by mouth."